Submersible cleaning robots for, for example, removing seaweed, algae, and shellfish, etc. having become attached to farmed fish nets and for removing dirt having become attached to ship hulls, etc. are known in the conventional technology (for example, see patent document 1).
Such a submersible cleaning robot cleans a cleaning subject item while moving along a submerged surface of the cleaning subject item by jetting high-pressure water from a cleaning nozzle unit towards this surface of the cleaning subject item. The cleaning nozzle unit is mounted on a rotary shaft provided on a robot body so as to be capable of rotation and rotates in unison with this rotary shaft due to a reaction force of the jetting of high-pressure water at the surface of the cleaning subject item.
Furthermore, a propeller generating a propulsion force for urging the robot body toward the surface of the cleaning subject item by rotating pursuant to a rotation of the rotary shaft is mounted on this rotary shaft.    Patent document 1: JP3592204